Check out Tk::Text.

Update: An example to get you started:

#!/usr/bin/perl -w

use Tk;
use Tk::Text;

my $mw = MainWindow->new(-name => 'test');
my $text = $mw->Text();


my $txt = "This is some\ntest text.";

#
# Insert some text.  The first arg is an index
# (it can be any of: qw(line.char end linestart lineend
#  wordstart wordend) and several others) and
# the second arg is the text to insert.
#
$text->insert('0.0', $txt);

# Place it in the window
$text->pack();

MainLoop;

#
# And to get the modified text later...
#
#my $new_text = $text->get('0.0', 'end');
[download]

bbfu
Seasons don't fear The Reaper.
Nor do the wind, the sun, and the rain.
We can be like they are.